Monthly Archives: October 2012

To get into the spirit, Lynn and I will be working late, in costume, and talking to guests about conservation and mummies.

We thought that for tonight’s event, it would be appropriate to lower the lights and do some ultraviolet (UV) examination of objects, and to talk about this process to those who visit the lab.

As we have explained in previous posts, visual examination is a critical first step of the conservation process. We can understand a lot about objects just by looking at them under good lighting and with magnification.

While most of our examination is initially carried out under visible light, we also use UV lamps (better known as black lights) to examine artifacts in order to make visible things that we cannot see otherwise. Examination of objects in the dark under UV allows us to see UV fluorescence of materials, and some materials exhibit unique or characteristic fluorescence. This often helps us characterize materials and to distinguish old restoration materials from original materials-for instance, shellac, used historically to repair objects, exhibits a characteristic bright orange fluorescence under UV.

For a great explanation of UV, along with some interesting images, check out this post on UV examination by my colleague Allison Lewis, conservator at UC Berkeley’s Phoebe A. Hearst Museum of Anthropology.

One of the boards from the inner coffin of Ahanakht, before treatment.

Previously I began to tell you about this multi-part artifact. Then, I was just starting to get acquainted with it. When conservators first look at any artifact, the first thing we think about is not where it’s from, not how old it is, not even what culture made it. The first and most important fact for conservators is what it’s made of. The material tells us what kind of problems it might have and what kind of treatments we can use or not use – it’s the starting point of everything we do.

The coffin boards are wood, with some paint applied. Four thousand year-old wood. Right away, that tells us something about what kind of wood it must be, since wood generally doesn’t survive so long in the archaeological record. Because there’s been a lot of research done on Egyptian materials, we can say with some confidence that the wood is cedar of Lebanon (Cedrus libani). Cedar is a prized wood because the trees produce chemicals that make them resistant to insect damage and various forms of rot.

A detail of the board showing construction details.

The first step of any treatment is careful examination. The coffin boards, despite being entombed thousands of years ago in the desert environment of Egypt and then brought to Philadelphia with its humid summers and desiccating winter heating seasons, appear to be in excellent condition for the most part; their most obvious problem being a thick coat of dust from uncovered storage for many decades. I documented the appearance of the board, noting its construction details, such as four wooden pegs and mitered edges. One curious feature was thin metal ribbons running in channels along the long axis of the board. I was unsure whether these were an original feature or something done in modern times to put the coffin back together. It seemed an unusually elaborate repair but the metal was in such good condition that I didn’t think it was 4000 years old. Even under a microscope, I couldn’t tell exactly what the metal was. There were slight traces of green corrosion, which usually means copper or copper alloy, but the metal was mostly dark grey and quite flexible, so it could be lead. I made a note to analyze it using our new portable X-ray fluorescence analyzer which has since happened and to do some research on Egyptian coffin technology. Dr. Joe Wegner, also an Associate Curator in the Egyptian Section, recommended a book about a similar coffin at the Boston Museum of Fine Arts (The Secrets of Tomb 10b) and there I found this information: “the sides have beveled edges fastened together by dowels and copper ribbons“. So it looks like those metal ribbons are original. Perhaps their unusually excellent condition has something to do with the cedar around them.

During treatment, showing dirt partially removed and tools used for cleaning.

Treatment was relatively straightforward. I used a HEPA-filtered vacuum with variable speed control to remove the loose dust from the surface of the board. Conservators choose their cleaning methods based on the type of dirt to be removed and the substrate from which it is to be removed. ‘Dry’ cleaning methods (those not using liquids such as water or other solvents) are generally less likely to damage the artifact and are preferred wherever possible, although care must still be taken to ensure that only the dirt is removed and not any of the original surface. By using a very small vacuum attachment at low speed and monitoring the process closely using a magnifying visor, I was able to clean the surface safely. Not very glamorous but I’ve discovered that this artifact has a pretty important role in the history of archaeological science – see my post on the Museum’s blog for information on that!

What can we do with a pXRF, you might ask? Well, Nina Owczarek provides a good overview about the use of this instrument in a previous post and also in a presentation which you can watch by following this link.

I’ve used a pXRF before, but it’s been awhile, so today Nina came up and gave us all a refresher. Essentially, x-ray fluorescence is a non-destructive analytical method that uses x-rays to identify elements present in objects or samples. This technique is particularly useful for characterizing pigments and metal alloy components, and that is what we’re using it for in the Artifact Lab.

A view of Nina and I discussing the pXRF from outside the lab

After examining a few artifacts visually, we had some questions about materials and wanted to do some further investigation with the pXRF. For instance, we are interested in these metal ribbons on the Ahanakht coffin boards (see Lynn Grant’s previous post about the boards).

The pXRF positioned in contact with the metal ribbons on one of the smaller coffin boards

After examination of these ribbons under the microscope, it was still difficult to determine what type of metal they are made of. With the pXRF, after a 180-second scan and using special software, a spectrum was produced that showed a large peak for copper and very small peaks for tin, iron, arsenic and lead. We haven’t been able to analyze the data much yet, but this does tell us that these are indeed made of copper.

We will follow this post soon with more information and interpretation of our results.

By now, many of you may be familiar with this object from it’s appearance in our recent media coverage:

Painted wooden coffin from the Late Period

This is a painted wood coffin from the Late Period, post-558 BC. It has been fairly inaccessible in storage until coming up to the Artifact Lab. Now that it’s up here, we’re realizing that it’s going to be a complex project, in more ways than one.

First of all, it’s a bit confusing who this coffin belonged to. In our records, is listed as the coffin of Tawahibre or Teker-Wah-Eb-Re. The mummy associated with the coffin was x-rayed in 1932 and examined in the 1970s and both times determined to be a woman in mid-adult life (about 40 years old). However, in 1946, the hieroglyphic text on the coffin was translated as identifying a male court official, the son of J-se(t)-N-Ese. Our curators are going to work to translate the text to see if we can figure out who the coffin belonged to…however…

The second complication is that, unfortunately, this coffin hasn’t aged particularly gracefully, and it is now very fragile and in poor condition. And even more unfortunately, the areas that contain much of the text are in the worst condition, with major losses to the painted surface.

Detail showing major paint loss across the foot area of the coffin

So, one of the first things we’ve done to improve the condition of the coffin and aid in translation is to remove years of accumulated surface dust using a soft-bristled brush and a HEPA-filtered vacuum. This made a big difference and already allows the text to be read more easily. I am now conducting cleaning tests to see how much more surface grime can be removed. I did some dry-cleaning (meaning cleaning without the use of solvents like water or alcohol) testing today using Groomstick, a natural rubber product similar in consistency to SillyPutty, and cosmetic sponges, and I’m pretty happy with the results. Look at how much more dirt I was able to remove with these products:

Okay, bear with me here-I’m going to explain the connection between one of the mummies here in the Artifact Lab, Wanamaker’s Department store, and the 1987 movie Mannequin.

PUM (Philadelphia University Museum) I is a mummy lying in a wood coffin, dating to 840-820 BCE. The mummy and coffin were exhibited at the 1904 World’s Fair in St. Louis and subsequently purchased by John Wanamaker as a gift for the museum. They were packed and shipped directly to the museum in early 1905. This is what PUM I looked like soon after arriving to the museum (click here) and this is what PUM I looks like now:

PUM I in his coffin

We don’t know who PUM I was-there are no identifying marks that are visible on the wrappings or coffin. We do know, however, that this person was a man-the body was x-rayed in 1932 and also autopsied early on by cutting a section of the wrappings away from the pelvic region, and determined to be an older man. Each end of the coffin does have some painted decoration-one end depicting Isis and the other her sister Nephthys, as protectors of the mummy.

One end of PUM I’s coffin showing the depiction of Isis in the center

One of our goals this year in the Artifact Lab will be to remove the deteriorated remains from the coffin and stabilize them for transport to the hospital for CT-scanning, so that we can learn more about this individual.

What does this have to do with mannequins, you’re wondering? Well, as most people in Philadelphia know, John Wanamaker, the man who purchased and donated PUM I to the Penn Museum, was a businessman from Philadelphia who founded the first department store here, Wanamaker’s. Last week my mom and I wandered into the old Wanamaker’s in Center City, now a Macy’s. It’s a beautiful building with the world’s largest playable organ (also built for the 1904 St. Louis World Fair), which is played every day of the week except for Sunday, as well as more often on special occasions.

My mom reminded me that one of my favorite childhood films, Mannequin, was filmed in the store, and it made me want to watch it again-it’s been a long time since I last saw it. But only today did it dawn on me that there is another reason to watch it, and it’s related (very loosely) to work: the mannequin character, played by Kim Cattrall, is from Ancient Egypt, living in the year 2514 BC, and the film begins in Egypt.

Kim Cattrall bandaged as a mummy at the beginning of the movie

If this doesn’t make you want to watch the movie, I don’t know what will. Alternatively, you could come check out PUM I in the Artifact Lab. We’ll let you know when we make a move to get him out of his coffin.

Let’s take a closer look at another object undergoing conservation treatment In the Artifact Lab.

Wall painting fragment from Deir el-Medina, Egypt

This is a wall painting fragment from a tomb wall in Deir el-Medina, located near the Valley of the Kings and Valley of the Queens. It dates to 1150 BCE. The painting substrate is a mud plaster mixed with straw, and the surface is painted to depict the standing figure of a diety in profile. At some point in the past, this fragment was set into a wood frame and encased in plaster.

The first step in the conservation process is to document the condition of the wall painting. Using Photoshop and a tablet computer, a condition map was created to highlight areas of loss, major breaks, and loose elements.

A basemap showing condition issues including major breaks and loose pieces (see key on right).

After recording its condition, I then started investigating the materials and methods used to mount and frame it. The wall painting fragment appears to be backed and surrounded with Plaster of Paris and set into a wood frame with beautiful dovetail joints.

Detail showing corner of frame with dovetail joints

At first, we thought that one option might be to leave it as is, but it was immediately evident that the plaster surrounding the painting was cracked and loose in areas. After prying some of the loose plaster away, I found that luckily, the plaster seen around the outside of the painting is only a thin skim coat layer, and that paper was used as a barrier layer in places between the painting and the plaster. I was hoping that it would be newspaper, providing clues as to when and where the framing occurred, but unfortunately, so far all I’ve found is plain paper.

I did find one clue, however, hidden on the inside of the frame-a sticker reading “DOUANE PARIS CENTRAL”. There is a portion of an identical sticker on the back of the frame, but it is much harder to read. A Google search of these words led me to conclude that this might be a customs sticker. Why there would be a customs sticker on the inside of the frame is unclear, but from this evidence, as well as the fact that we know that this painting was purchased from Joseph Brummer, a dealer who ran galleries in Paris and New York, we can assume that this painting was mounted and framed before it was purchased by the museum in 1925.

We will continue examining and carrying out research on the wall painting fragment to understand its current condition problems, and also how we will approach stabilizing it for future display. We will provide updates as we work on this object!

The outer coffin of Ahanakht, assembled, in an early photograph from the Museum Archives

One of the big projects the new Artifact Lab space is allowing us to work on is the Inner Outer Coffin of Ahanakht (E 16218A-P). This artifact, currently in at least 15 pieces, has a long inscription in Hieratic script on the interior surfaces that Dr. David Silverman and his graduate student Leah Humphrey are working on transcribing and translating.

The scholars know that the coffin was made for an Egyptian named Ahanakht because his name is in the inscription.

Dr. Jennifer Wegner, Associate Curator in the Egyptian Section, showed me Ahanakht’s name as it would appear on the coffin inscription.

We know the coffin had been reassembled at one time but since was taken apart, probably to make it easier to store. But that made it hard to access, since many of the boards are very large (the largest boards are 8.5 feet long), very heavy and awkward to move and space in storage is limited. In the Artifact Lab, we had shelving custom built to accommodate the coffin boards so we could treat them and the Egyptologists could finally read their inscriptions.

The custom built steel shelving to house the large, heavy coffin boards in the Artifact Lab

Because the coffin is in many pieces which shouldn’t need a lot of conservation, it’s a perfect project for the staff conservators who will only be spending occasional stints in the Artifact Lab (unlike Molly Gleeson, the project conservator) so last Sunday I began work on one of the smallest of the coffin boards. It’s been interesting. I’ll fill in the details in my next post.

This is the first in a series of posts describing objects undergoing conservation treatment In the Artifact Lab.

This object appears to be a mummified falcon.

Mummified falcon, before treatment.

I say “appears to be” because we cannot be certain that there is a falcon, or any animal remains for that matter, under the wrappings. In Ancient Egypt, it is known that in addition to mummifying animals, “false” animal mummies were made-from the outside they look like they contain an animal but on the inside, there may only be a bundle of mud and straw, or just a bone or two, or some fur or feathers. These false mummies could have been made to deceive the buyer, but they may also have been made when there was a scarcity of that particular animal, and may have still been considered complete offerings.

Animal mummies were created for a variety of reasons-this article by Salima Ikram, the first in a recent issue of AnthroNotes published by the Smithsonian’s National Museum of Natural History, summarizes the topic well, putting them into 5 categories: pets, food, sacred, votive, and “other.” The article explains that, yes, some animals were mummified because they worshipped, but many were mummified as offerings to specific dieties, and others because they were considered beloved pets.

This falcon mummy may have been created as an offering to the god Horus. It was excavated from Abydos in 1914 through the Egypt Exploration Fund (later Egypt Exploration Society) through financial support of the Penn Museum. Although the museum’s records do not include a specific date, it is likely that it dates to the Late or the Graeco-Roman Period-many animal mummies date to this time and the decorative linen wrappings seen on this object were popular during these periods as well.

This mummy is elaborately wrapped with strips of natural and dyed linen and details on the head and face are outlined in a brown/black paint. While the mummy is generally very well preserved, it is currently unstable because the head/neck area is partially detached and the linen strips at the feet are in poor condition-some are completely detached.

After fully documenting and researching this object, conservation treatment will include light surface cleaning, stabilization of the head/neck, and stabilization of the wrappings as needed. A storage/handling support has also been created to allow the mummy to be studied without needing to directly touch the object. This work will also allow the mummy to be safely x-rayed and/or CT-scanned. We will post updates on this object as we uncover more details and begin the treatment!

And what a week it has been! We are officially moved in to our new conservation lab, up on the 3rd floor of the museum and work is now underway in the Artifact Lab.

A view of the Artifact Lab from the entrance to the gallery

Since we opened on Sunday, we’ve spent the week getting situated in our new lab, preparing our work space, tools, and materials, and starting to examine several of the objects we’ll be working on over the next few months. We have a fascinating variety of objects in the lab-including mummified human remains, mummified animals, and funerary items such as painted and inscribed coffins and coffin boards (parts of coffins). These objects have spent many years in storage, some of them since being acquired by the museum over 100 years ago. One of the huge advantages of working on them in the new Artifact Lab is that we have the space, suitable lighting, and proper equipment to thoroughly examine and research these objects, and in the last few days, it quickly became clear that in several cases, we have our work cut out for us.

This painted wood coffin, for instance, is going to be a major project-

Wood coffin dating to the Late Period (post 558 BCE). Notice the heavy layer of grime and significant cracks in the paint and gesso layers.

It’s surface is heavily obscured by dust and grime, and it also has significant structural issues as well, including severe cracks that extend though the paint, gesso and wood and significant losses to the painted surface. We can already tell that this will be a project that will be ongoing in the lab for awhile.

Oh, and in addition to our regular conservation lab work, did I mention that we’ve spent a lot of time this week speaking with the public? Our work will always be visible to anyone who stops by-our Head Conservator Lynn Grant appropriately refers to the space as a fishbowl-there is literally, nowhere to hide (and if there was I wouldn’t tell you). But twice a day, 11:15am and 2:00pm Tuesday-Friday and 1:00pm and 3:30pm Saturday and Sunday, we open the windows to answer questions and speak about our work. We also have the advantage of using our new Smartboard to show additional images-photos showing the progress of our work and images collected through research.

We use this Smartboard for presentations and also for communicating to visitors when we are working.

Stay tuned for upcoming posts featuring some of the objects that we’ll be working on in the Artifact Lab, and some of our latest discoveries!